Plant growth regulators affect the physiology of plant growth and influence the natural rhythm of a plant. More specifically, plant growth regulators may, for example, reduce plant height, stimulate seed germination, induce flowering, darken leaf coloring, minimize lodging of cereals, slow grass growth on lawns, reduce boll rot and provide better boll retention in cotton.
The plant growth regulator (PGR) known trivially as mepiquat chloride is well known and has been combined with other plant growth regulators, including cytokinins, as disclosed in U.S. Pat. Nos. 4,886,545, 4,747,868 and 4,637,828 (the entire content of each being expressly incorporated hereinto by reference.).
The endosperm of coconut, Cocos nucifera (known as "coconut milk" in its liquid form) is known to contain hexitols (e.g., myo-inositol and scyllo-inositol) and cytokinins which promote plant growth. Wilkins, "The Physiology of Plant Growth and Development", Chapter 3, pp. 85-123 (1969), and Steward et al, "Plants, Chemicals and Growth", pp. 108-111 and 134-138 (1971).
According to the present invention, synergistic plant growth results have been obtained by applying to plants a PGR composition which includes a plant growth regulating effective mixture of (A) a N,N-dimethyl piperidinium salt (preferably mepiquat chloride), (B) a hexitol (myo-inositol), and optionally (C) a compound which promotes cytokinesis in plant cells (i.e., a cytokinin).